1. Field of the Invention
The present invention relates to image generating method and apparatus for generating a desired display image on an image display medium. Particularly, it relates to image generating method and apparatus for generating a display image on an image display medium capable of repetitive rewriting thereby providing availability like a paper.
2. Description of the Related Art
With the progress of information society in recent years, there have been increased the chances of reading computerized information in the form of a display image on a display and also in the form of a printed paper provided by printing a display image on a paper. In this situation, it has been required that the image on the display is easily viewable like the image on a printed paper, easily portable like a printed paper and usable in spite of being folded. Further, it has been required that the printed paper is capable of repetitive rewriting like the display and also representing an animation.
In order to meet these requirements, a new media having respective merits of the display and the printed paper, such as electronic paper and paper-like display, has been proposed in recent years and therefore, the development of technology is promoted toward the practical use of new media actively.
As for the technology for realizing the electronic paper and the paper-like display, there are studied various technology, for example, image displaying technique to make use of electrophoretic effect, image displaying technique to make use of the rotations of colored particles called xe2x80x9ctwist ballsxe2x80x9d, technique to change a display image in reversibility by the thermal rewritable method, technique to apply a liquid display method, technique to display an image by moving colored particles in particles, etc.
Focusing attention on method of generating a display image, the above-mentioned electronic paper and paper-like display are divided broadly into two types. One is a type that writing means for a display image is integrated with a medium for displaying an image, which will be referred xe2x80x9cimage display mediumxe2x80x9d hereinafter. The other one is a type that the writing means for a display image is separated from the image display medium to form an image generating apparatus. In this case, the display image is formed in the image display medium by the image generating apparatus.
The former type that the writing means is integrated with the image display medium has the advantage of possibility to rewrite the display image each time. However, the image display medium has a complicated structure to exhibit the limit for low-cost. Therefore, it is supposed that it is difficult to spread this type of medium as new media in place of paper. To the contrary, the latter type that the writing means is separated from the image display medium has the advantage of simplifying the structure of the image display medium itself, which is effective in saving the manufacturing cost. Therefore, it is expected to realize the utilization of this medium in the form closer to paper.
In the latter type, however, the image generating apparatus (as the wiring means) is generally required to have a number of exclusive mechanisms in order to form an appropriate display image in the image display medium. This requirement is an obstacle to the realization of low-cost for the total system including the image generating apparatus.
Additionally, in the conventional technology, there is a tendency for a processing time to increase in forming the display image in the image display medium while using the image generating apparatus as the writing means. Therefore, a high-speed processing, such as printing operation of printed papers, has been unfulfilled in the present circumstances.
Under such a circumstance, it is therefore an object of the present invention to provide image generating method and apparatus that allow a desired display image to be formed in an image display medium used as an electronic paper or a paper-like display, by means of a low-cost system and that make possible to perform an operation to generate a display image in the image display medium at high speed.
The present invention provides an image generating method of generating a desired display image in a rewritable image display medium by transcribing a perforated image of a stencil sheet to the image display medium, the stencil sheet being attached to a rotary drum, the method comprising the steps of: preparing the image display medium including: a film body having a base and a number of microscopic film pieces connected with each other through the base, the microscopic film pieces having light-blocking effect and corresponding to respective pixels forming the desired display image; a supporting member having a main face formed to support the film body thereon, the supporting member being provided, on the side of the main face, with a number of receiving spaces defined by partitions, the receiving spaces corresponding to the microscopic film pieces respectively and also allowing the microscopic film pieces to be moved therein independently; and a cover member arranged on the main face of the supporting member while interposing the film body therebetween, the cover member having light-transmitting effect, and allowing the microscopic film pieces of the film body of the image display medium to be selectively absorbed to either the cover member or the partitions in accordance with the perforated image of the stencil sheet, thereby generating the display image in the image display medium.
The image display medium used in the above image generating method is an image display medium called xe2x80x9celectronic paperxe2x80x9d or xe2x80x9cpaper-like displayxe2x80x9d. As the film body for this image display medium, it is possible to adopt an insulating film having light-blocking effect, for example. The numerous microscopic film pieces are provided by forming a number of C-shaped notches in the insulating film having a desired size, etc. In the film, a film""s portion (area) surrounded by each notch forms one microscopic film piece corresponding to a display pixel. A film""s portion (area) between the adjoining microscopic film pieces forms the base of the film body.
On the main face of the supporting member, the film body is supported by the supporting member. The cover member having light-transmitting effect is arranged on the film body supported by the supporting member. Thus, the film body is sandwiched between the supporting member and the cover member.
On the side of the main face of the supporting member carrying the film body, the numerous receiving spaces are defined corresponding to the microscopic film pieces respectively. The receiving spaces allows the microscopic film pieces to be moved therein independently.
In the above-constructed image display medium, for example, by fixing respective electrical charges of the supporting member and the cover member (electret), the numerous microscopic film pieces of the film body are respectively absorbed to either the cover member or the partitions forming the receiving spaces due to electrostatic induction and further, such an absorbed condition is maintained. In the medium""s portion where the corresponding microscopic film piece is absorbed to the cover member, light is blocked up by the microscopic film piece. While, in the medium""s portion where the corresponding microscopic film piece is absorbed to the partition of the supporting member, light can pass through the film body and enter the receiving space. Therefore, it becomes possible to switch, for every microscopic film piece, between one state that the microscopic film piece is absorbed to the cover member to block up the light and another state that the microscopic film piece is absorbed to the partition of the supporting member to penetrate the light, selectively. That is, for every display pixel, it is possible to control blockade and transmission of light, allowing an image corresponding to this light control to be displayed.
In the image generating method of the invention, the microscopic film pieces of the film body are absorbed to either the cover member or the partitions selectively in accordance with the perforated image of the stencil sheet attached to the rotary drum. Consequently, the perforated image of the stencil sheet is transcribed to the image display medium, forming a desired display image.
In detail, it is carried out to make the stencil sheet attached to the rotary drum take an electrical charge so that the stencil sheet produces a contrast of charge corresponding to the perforated image. Further, it is carried out to make the microscopic film pieces of the film body move in accordance with the contrast of charge. Then, the microscopic film pieces are selectively absorbed to either the cover member or the partitions by electrostatic induction. Consequently, the image display medium has a display image formed to correspond to the perforated image of the stencil sheet.
In order to allow the stencil sheet to have a contrast of charge in accordance with the perforated image, a paper where a thermosensitive film is laminated on a perforated carrier coated with conductive agents is suitable for the stencil paper. Alternatively, a paper where a thermosensitive film comes in close contact with a conductive film through a wax having conductivity is suitable for the stencil paper, as well. The stencil sheet is produced by forming a perforated image corresponding to the display image, in the thermosensitive film of the stencil paper. Subsequently, by attaching the resulting the stencil sheet to the rotary drum and further electrizing the stencil sheet, the contrast of charge is produced to correspond to the perforated image in the stencil sheet.
In order to transcribe the perforated image of the stencil sheet to the image display medium thereby generating a desired display image therein, it may be carried out to emit or suck air through the rotary drum having the stencil sheet attached thereto. Then, a pressure of the above air acts on the image display medium through the stencil sheet. In this case, the cover member is formed to have air permeability. Owing to the pressure of the air, the microscopic film pieces of the film body are moved in accordance with the perforated image of the stencil sheet and selectively absorbed to either the cover member or the partitions defining the receiving spaces. In this way, it is possible to produce a desired display image corresponding to the perforated image of the stencil sheet, in the image display medium.
In addition, the present invention provides an image generating apparatus for generating a desired display image in a rewritable image display medium. The image generating apparatus is formed by medium loading means for transferring an image display medium and image generating means for generating the display image in the image display medium transferred by the medium loading means. In the image generating apparatus, the image display medium to be transferred by the medium loading means includes a film body having a base and a number of microscopic film pieces connected with each other through the base, the microscopic film pieces having light-blocking effect and corresponding to respective pixels forming the desired display image, a supporting member having a main face formed to support the film body thereon, the supporting member being provided, on the side of the main face, with a number of receiving spaces defined by partitions, the receiving spaces corresponding to the microscopic film pieces respectively and also allowing the microscopic film pieces to be moved therein independently, and a cover member arranged on the main face of the supporting member while interposing the film body therebetween, the cover member having light-transmitting effect.
Further, in the image generating apparatus, the image generating means includes a rotary drum having a stencil sheet attached thereto. Corresponding to a perforated image of the stencil sheet attached to the rotary drum, the microscopic film pieces of the film body of the image display medium are selectively absorbed to either the cover member or the partitions. In this way, since the perforated image of the stencil sheet on the rotary drum is transcribed to the image display medium, it becomes possible to generate a desired display image in the image display medium.
In detail, for example, the image generating means allows the stencil sheet attached to the rotary drum to take an electrical charge thereby making the stencil sheet produce a contrast of charge corresponding to the perforated image. Further, the image generating means allows the microscopic film pieces of the film body to move in accordance with the contrast of charge. Then, the microscopic film pieces are selectively absorbed to either the cover member or the partitions by electrostatic induction. Consequently, the image display medium has a display image formed to correspond to the perforated image of the stencil sheet.
Alternatively, the image generating means may be adapted so as to emit or suck air through the rotary drum and also adapted so as to make the microscopic film pieces of the film body move in accordance with the perforated image of the stencil sheet by making use of air pressure of the air through the rotary drum. In this case, the cover member is formed to have air permeability. Owing to the pressure of the air, the microscopic film pieces of the film body are moved in accordance with the perforated image of the stencil sheet and selectively absorbed to either the cover member or the partitions defining the receiving spaces by electrostatic induction. In this way, it is possible to produce a desired display image corresponding to the perforated image of the stencil sheet, in the image display medium.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompany drawings.